By this command is possible enter in Super User mode, sometime is necessary use the command:sudo su
Dopo
aver dato il comando su, ci verrą chiesta la password.The indication that we are Super User is the characther: #at the end of the prompt line.

example:
root@enrico-MM061:/home/enrico#For exit from the super user mode use the command:exit

1...9) it tell us the permission and means:r readingw writingx execution- not assigned

The permission are groupped for:1,2,3)
permissions assigned to the owner4,5,6) permissions assigned to thegroup7,8,9) permissions assigned to all the users

A)
indicates the number of connections to the component while for folders indicates the number of extra blocks.B)
it is the name of the owner of the file or the directory.C) is the group membershipD)
dimensionsE) date and time of creation or last modification

It is used to install the packages.
EXAMPLE:sudo apt-get install gedit
Install gedit

sudo
apt-get remove <package>

Remove the package and all dependencies not used from other packages.

sudo
apt-get remove <package>

Remove all dependencies not more used from the package.

sudo
apt-get purge <package>

Similar to apt-get remove, but also remove the
configuration files related to the package.

sudo
apt-get update

It allows us to update the packages in our system.
If a package requires the installation or removal of new dependencies the package will not be updated by the update command.
To effect these changes will also have to use upgrade command (see below).

sudo apt-get
upgrade
Upgrading new packages that require installation or removal of new dependencies.
It 'a good idea to give commands in the sequence show below: sudo apt-get update
and then sudo apt-get upgrade

sudo
apt-get clean

Removesthe filesare no longerusedin our system.

sudo
apt-get autoremove

Removes files marked as no longer used

sudo
apt-cache search <word>

It is use for find a packages that contain the specified word

sudo
apt-cache show <package>

This command show the information regarding the package

sudo
apt-cache depends <package>

This command show the packages that are necessary for a package.

sudo
apt-cache showpkg <package>

This command show the version, the reverse depens and the dependecies of a package Example:

iwconfig command is similar to
ifconfig command, but is dedicated to the Linux wireless interfaces.
It is used to manipulate the basic wireless parameters such as ssid,
mode, channel, bit rates, encryption key, power and much more.